Intravacc yesterday announced a partnership with Leiden University Medical Center (LUMC) to develop and evaluate a new nasal spray corona vaccine in a clinical phase-I/II study. This new vaccine, Nanovac, is based on microscopic soluble nano-spheres, containing synthetic mini proteins that, when administered as a nasal spray, directly protects the upper respiratory tract including nasal passages and throat (mucosa) before the virus reaches the lungs.

The planned clinical phase-I/II study is made possible in part by the Top Consortium for Knowledge and Innovation (TKI) of Health~Holland, part of the Dutch top sector Life Sciences & Health, which plays a connecting role between the business community, government, research institutes, patients and social organisations.

A doctor and his team from LUMC, responsible for LUMC’s Translational Nanobiomaterials and Imaging department, spent more than a year working on the new, sustainable and simple nasal spray vaccine. The pre-clinical studies in animals showed surprisingly positive results. The phase-I/II clinical study is led by Dr Leo Visser of the Infectious Diseases Department of the LUMC. Intravacc will focus on a number of additional and preliminary pre-clinical exercises and the process development research of the vaccine through a scalable vaccine production process using its expertise in GMP vaccine production. The vaccine will be tested on healthy volunteers to evaluate safety and tolerability. This phase-I/II clinical trial is expected to start at the end of 2022 and the first study data is expected in the first half of 2023.

The nano vaccine candidate is not only based on spike protein, but also other target proteins in the coronavirus. It consists of a nanoparticle formulation containing multi-epitopes polypeptides of the immunogenic spike (S) protein of SARS-CoV-2 (COVID-19), as well as other 100 per cent conserved epitopes derived from distinct coronavirus proteins of which important targetting has already been identified for inducing a complete humoral systemic and mucosal immune response, and cellular immunity response, both neutralising antibodies and T cells, both for immediate immunisation, and for a longer-term defence.

To enhance the effectiveness, the adjuvant hepatitis B core antigen HBcAg is used, which already has a proven effect in a nasal spray vaccine against liver inflammation. The HBcAG particle has been safely administered intranasally, serving as a carrier for nasal route and an immunostimulant for the mucosal immune cells of the nasal passages and upper respiratory tract. The vaccine does not apply the more recently used mRNA technique or of inactivated cold viruses (vectors).

The other COVID nasal spray vaccine that Intravacc is working on, Avacc-10, uses OMVs, vesicles that bacteria communicate with and that serve as a platform to transport a protein that can (eventually) fight COVID.

In addition to COVID-19, the platform technologies on which these vaccines are based can also be used for the development of vaccines against a variety of other diseases. Several clinical studies with vaccine candidates developed on these platforms and administered by nasal spray or injection, have demonstrated safety for use in humans. Nanovac and Avacc-10 can be quickly adapted to new COVID virus variants and then produced rapidly in large quantities and are cheaper than the existing vaccines. In addition, they can be stored at room temperature, which simplifies transport over longer distances. This makes these vaccines an ideal solution for lower-income countries with a more limited medical infrastructure.